Feedstock-dependent mobility of pyrogenic carbon colloids under naphthalene: dominant role of zeta potential and adsorption behavior.

Humidity dependent frictional properties of single crystal quartz at low to high slip velocities

The porous nature of eolian dune sediments enables post-depositional silt and clay to be added to the dune profile with an open-ended timeline. The allochthonous silt results in depositional age-heterogeneity between sand and silt which could encumber investigations that employ portable optically stimulated luminescence (OSL) readers to construct luminescence profiles using unprocessed bulk samples. To establish an approach for ascertaining the relative timing of the introduction of silt, this study used a portable OSL reader to assess the level of allochthonous silt in the upper parts of ca. 15 ka old postglacial eolian dunes in central Alberta, Canada. Four dune profiles were sampled using an auger at 10 cm intervals to a depth of 300 cm. Each sample was sieved into sand and silt with clay fractions (>0.063 mm and <0.063 mm) and then measured with IRSL and post-IR blue OSL using a portable OSL reader. Signals of the bulk samples were also measured for comparison. Results showed that the difference in signal intensity between the bulk samples, sand, and silt with clay fractions was insignificant, suggesting no substantial allochthonous silt was introduced into the area during the Holocene. An alternative source for the silt could be in-situ frost weathering of quartz sand in dune sediment as confirmed by grain surface microtextures from scanning electron microscopy.

Use of organic corrosion inhibitors is an economical and effective way to combat internal corrosion in oil and gas transmission pipelines. Organic corrosion inhibitors are typically amphiphilic molecules, with a hydrophilic head group and a hydrophobic tail, which provide protection by adsorption on the metal surface. Therefore, understanding the adsorption phenomena has significance for prediction of corrosion inhibition performance. In this contribution, a quartz crystal microbalance with dissipation monitoring (QCM-D) equipped with a flow control unit was used for investigating the electrode/electrolyte interface to understand the nature of the adsorbed layer and compare the influence of head group change (with same alkyl tail length) for two model inhibitor compounds, tetradecyldimethylbenzylammonium (BDA-C14) and tetradecyltetrahydropyrimidinium (THP-C14) on a noble substrate, gold, in 1 wt.% aqueous NaCl solution. The whole adsorption process happened in a single step for BDA-C14 model inhibitor compound versus multiple steps of adsorption observed in the case of THP-C14 molecules evident by multiple plateaus in frequency and dissipation change curves with respect to time during adsorption. Similar observations about the multi-layer adsorption with comparatively rigid inner layer has been made from atomic force microscopy (AFM) experiments for adsorption of THP-C14 on mica by topographical evolution with respect to time and analysis of the AFM force curves which shows multiple breakthroughs through the adsorbed inhibitor layer. While the QCM-D and AFM findings align well for BDA-C14 model inhibitor compound in terms of single step adsorption, adsorbed mass, adsorbed layer thickness etc., it should be noted that for THP-C14 model inhibitor compound, adsorbed mass analysis using QCM-D indicates a significantly thicker adsorbed layer, which contradicts the AFM findings for THP-C14. Overall, employing multiple sensitive techniques in parallel provides complementary qualitative and quantitative insights into the adsorption behavior of organic inhibitors.

In electrolyzers, the electrocatalytic splitting of aqueous electrolytes is typically impeded by the sluggish kinetics of the Oxygen Evolution Reaction (OER) at the anode. In established alkaline electrolysis technologies, NiOOH anodes are commonly employed and have been the subject of extensive studies using various analysis methods, such as Raman spectroscopy. [1-4] In this study, we emphasize the origin of the vibrational modes of a NiOOH Raman spectrum, with the objective of attaining a more profound understanding of the surface structure of NiOOH before and during the OER. Additionally, we illustrate the impact of varying pH values on the OER activity and the surface structures of the NiOOH electrodes, with the aim of providing a comprehensive understanding of potential-dependent structural changes.The potential dependent surface structural changes of NiOOH are investigated using in situ Surface Enhanced Raman Spectroscopy (SERS) in electrolytes of varying neutral and alkaline pH. Isotope labeling experiments, employing D2O and H2 18O, were conducted to gain additional insights in the measured Raman modes, from possible peak shifts induced by the isotopes. Furthermore, Density Functional Theory (DFT) calculations on various NixOy(OH)z were performed to assign the peaks in the Raman spectrum. Utilizing this comprehensive set of experimental and theoretical data, we demonstrate that the surface structure of NiOOH is predominantly deprotonated under both alkaline and neutral pH conditions. Additionally, we discuss the prevailing view on the formation and detection of superoxides using Raman spectroscopy on NiOOH. [3,4]Moreover, while performing the OER on NiOOH under weak alkaline pH values, SERS reveals a band at 1040 cm-1, which has not yet been reported. Further Cyclic Voltammetry (CV) studies at various pH levels also show significant changes in OER region. Complementary Electrochemical Quartz Crystal Microbalance (EQCM) measurements reveal pH-dependent changes in the electrode mass at high potentials, which correlate with the variations observed in the CVs and SERS spectra. The variations in the CVs are rationalized in terms of local pH changes at the electrode surface. Combining the results from the various techniques we discuss the impact of pH and potential dependent surface changes on OER kinetics and its underlying mechanism.(1) Klaus, S.; Cai, Y.; Louie, M. W.; Trotochaud, L.; Bell, A. T. J. Phys. Chem. C 2015, 119 (13), 7243–7254.(2) Merrill, M.; Worsley, M.; Wittstock, A.; Biener, J.; Stadermann, M. Journal of Electroanalytical Chemistry 2014, 717–718, 177–188.(3) Lee, S.; Chu, Y.-C.; Bai, L.; Chen, H. M.; Hu, X. Chem Catalysis 2023, 3 (1), 100475.(4) Diaz-Morales, O.; Ferrus-Suspedra, D.; Koper, M. T. M. Chem. Sci. 2016, 7 (4), 2639–2645. Figure 1

The 2D structure and unique properties of MXenes have attracted significant research interest. In this study, Ti3C2 MXene was functionalized with cholinium amino acid ionic liquids ([Cho][AA]s) to synthesize IL@Ti3C2 MXene, aiming to expand interlayer spacing, enhance surface functionality, and improve CO2 adsorption performance. The modification effectively increased the interlayer spacing, facilitating superior adsorption properties compared to pristine Ti3C2 MXene. The IL@Ti3C2 MXene composites were characterized using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Raman Spectroscopy, Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDX), and Brunauer-Emmett-Teller (BET) surface area analysis, while CO2 adsorption was evaluated via Quartz Crystal Microbalance (QCM) at 288.15-308.15K and pressures up to 1bar. Adsorption isotherms followed the Langmuir model, suggesting a predominant chemisorption mechanism involving amine functionalities. At 298.15K and 1bar, Ti3C2 MXene exhibited a CO2 adsorption capacity of 1.95mmol/g, while IL@Ti3C2 MXene composites displayed enhanced adsorption: [Cho][Arg]@Ti3C2 (3.25mmol/g), [Cho][His]@Ti3C2 (2.92mmol/g), and [Cho][Tyr]@Ti3C2 (2.64mmol/g). These improvements were resulted from electrostatic interactions, hydrogen bonding, Lewis acid-base interactions, and interlayer expansion. The exothermic nature of adsorption, confirmed by negative enthalpy (ΔH) values, indicates an energetically favorable process.

Eco-friendly QCM sensor based on biochar-functionalized nanofibers for rapid and selective detection of hydrogen chloride gas.

To treat acute myocardial infarction immediately after reperfusion, we previously engineered an intravascularly infusible decellularized extracellular matrix (iECM) biomaterial that exerts immunomodulatory and pro-reparative effects. However, the impact of the heterogeneous contents of iECM on infarct localization and downstream biological function is unknown. Using liquid chromatography, iECM is separated into a high molecular weight (MW) and low MW component. Mass spectrometry confirms compositional similarity, while biochemical assays and transmission electron microscopy highlight differences in biochemical features and structure, revealing a nanofibrillar high MW component and a globular peptide low MW. Quartz crystal microbalance studies show binding of each component to basal lamina ECM proteins and endothelial cell surface receptors under flow, demonstrating the specificity of ECM biomaterials to permeable vasculature.In vivo, the low MW component reduces vascular permeability, while neither component alone achieves the retention levels of complete iECM. Using single-nucleus RNA sequencing to probe bioactivity, both components elicited comparable angiogenic, immunomodulatory, and pro-reparative transcriptional programs. These findings illustrate that highly coupled materials and biological characterization uncover fundamental behaviors and properties of iECM biomaterials. Additionally, we show the unique binding behavior of iECM to the gaps of permeable vasculature, which could be exploited for future nanomaterial design.

Waste quartz crucibles (WQCs), produced as by-products in the fabrication of monocrystalline silicon rods, have become a significant recycling target due to the rapid growth of the photovoltaic industry. WQCs serve as an excellent precursor for synthesizing high-purity cristobalite sand, with an SiO2 content exceeding 99.995%. This study introduces a novel approach that integrates high-temperature crystallization-induced purification with acid leaching to convert WQCs into cristobalite. We systematically investigated the effects of calcination parameters (temperature and time) on cristobalite formation and characterized the distribution of aluminum and titanium (Al/Ti) in pre- and post-crystallization samples using depth profiling techniques. The results indicate that WQCs can be completely transformed into cristobalite after calcination at 1600 °C for 6 h. Employing these optimized conditions (1600 °C for 6 h) not only achieves a rapid crystallization rate but also effectively drives the migration of Al and Ti impurities to the surface and crack regions of the cristobalite matrix. The crystallization process enhances the purification of WQCs by redistributing impurities during the phase transformation. Consequently, the resulting cristobalite sand achieves an SiO2 content exceeding 99.998% after acid leaching. Therefore, this work offers a dual solution to both enhancing the value of WQCs and mitigating the scarcity of high-purity quartz sand raw materials.

ABSTRACT Pedogenetic processes or phenomena not directly related to pedogenesis can strongly influence soil formation. This study aimed to identify the origin of the abrupt textural difference and the deep, dark horizon in a soil profile located in southern Brazil by examining pedogenetic processes and sedimentology. The research was conducted in the geomorphological province of the Coastal Plain of Rio Grande do Sul, characterized by marine and eolian sedimentary deposits from the Quaternary (Pleistocene) period, formed during alternating humid and arid climates. In this region, rapid observations of soil profiles were conducted, and one soil profile was selected for detailed study. The studied soil is strongly acidic, pH(H 2 O) ≤4.7, with low cation exchange capacity (CEC ≤5 cmol c kg -1 ) and base saturation, attributed to the high quartz sand content. Micromorphological analysis revealed sub-rounded to sub-angular quartz grains, suggesting that the sediments forming the soil were transported over long to medium distances. In terms of indicators used to assess lithological discontinuity, a difference of 0.20 or greater was observed in the fine sand/total sand ratio (FS/TS), and a uniformity value (UV) greater than |0.60| was found between horizons Ap, 2E, and 3Ab1. This same trend appeared in the cumulative curve and mean sand diameter across these adjacent horizons, indicating an allochthonous origin of the soil and that sedimentary processes buried the deep dark horizon. The high aluminum oxalate/soil organic carbon ratio (Alo/SOC) in 3Btg (1.6/2.0) than in 3Ab1 (1.6/14.3) indicated another source of Alo besides complexation with SOC, which is associated with the formation of low-crystallinity aluminosilicates rather than an Al-humus complex. The significant presence of low-crystallinity kaolinites confirms this finding. Interstratified smectite-kaolinite was identified by the asymmetry of the primary and secondary reflections of kaolinite, indicating that, despite the low base saturation, drainage impediment favors an intermediate weathering condition in the soil. Sediment deposition of sandy parent material was the main factor responsible of the abrupt textural change at greater depth. Deep dark horizons 3Ab1 and 3Ab2 were not formed through the pedogenetic process of podzolization but were instead buried by depositional processes that formed the Coastal Plain of Rio Grande do Sul.

In dye-sensitized solar cells (DSCs), while increasing dye loading (e.g., with N719) enhances light absorption, excessive loading induces molecular aggregation, which consequently compromises device performance. The introduction of coadsorbents such as chenodeoxycholic acid (CDCA) effectively suppresses this aggregation; however, competitive adsorption between coadsorbents and dye molecules carries the risk of insufficient dye loading. Achieving an optimal balance between coadsorbent and dye concentrations requires precise quantification of their respective surface masses. Unfortunately, no simple method currently exists to directly determine the individual molecular masses within the mixed adsorption layer on TiO2 surfaces. To address these challenges, this study employed temperature-modulated quartz crystal microbalance (QCM) technology, which revealed a novel characteristic of significant thermal stability differences between the N719 dye and CDCA molecules on the TiO2 surface. Building on this finding, we developed a thermally selective quantitative detection approach that enables the direct quantification of N719 and CDCA adsorption on the TiO2 surface. This study has also innovatively transformed the detrimental high-temperature desorption of CDCA into an advantageous opportunity for interface engineering, establishing a novel adsorption site thermal maneuver supplementary sensitization (ASTM-SS) strategy. The sensitization process is accomplished through three consecutive steps, including CDCA-directed assembly of ordered dye monolayers, thermally selective CDCA removal for active site regeneration, and supplementary sensitization to achieve optimal surface coverage. This approach enhances the N719 loading on TiO2 by 126.7%, while photovoltaic tests demonstrate a 156.3% improvement in short-circuit current density (Jsc) and a corresponding enhancement in power conversion efficiency. Our work not only provides an innovative approach for the analysis of coadsorption systems but also introduces a new paradigm for solar cell interface engineering, offering critical guidance for the development of efficient and stable devices. Furthermore, this strategy demonstrates broad universality and holds potential application value in other multimolecular adsorption systems.

An innovative experimental device to quantify the water relative permeability and in situ water retention curves of unconsolidated porous media

The utilization of hydrocyclones dates back more than a century. As the key channel for multiphase flow, the inlet chamber exerts a notable influence on the separation efficiency of hydrocyclones. Conventional feed bodies mainly adopt straight lines as guidelines. During the transition of fluid from linear motion to circumferential motion, significant kinetic energy loss and particle misalignment are exhibited, resulting in relatively low classification accuracy of the hydrocyclone. Therefore, in this study, a hydrocyclone featuring a complex curved inlet chamber structure was designed, and numerical analysis was employed to examine the particle distribution and aggregation characteristics within both the inlet chamber and the hydrocyclone. Supplemented with RSM/VOF/TFM simulations and quartz sand experimental validation, this study compares the separation performance of the complex curved inlet with the conventional linear inlet. The results indicate the following: when particle sizes are small, particles are dispersed throughout the hydrocyclone and inlet chamber, exhibiting a disordered state, which leads to poor classification performance. As particle size increases, particles gradually form layers along the radial direction; larger particles tend to accumulate on the hydrocyclone wall. When the particle concentration is maintained within a specific range, it promotes the migration of fine particles toward the center, thereby reducing the likelihood of fine particles entering the outer vortex and allowing for more precise classification of fine particles. As the particle concentration increases, the cutting ability of the hydrocyclone progressively diminishes; when the concentration exceeds 20%, the maximum underflow recovery rate for particles smaller than 50 µm is only 60%, resulting in significant coarse overflow and a notable decrease in classification precision. Furthermore, as the inlet concentration increases, the dispersion index for 0.5 µm particles ranges from 0.6 to 1.6, for 4 µm particles from 0.6 to 1.4, and for 60 µm particles from 0.6 to 1. The decreasing dispersion index indicates an increasing classification force, which aids in the formation of a coarse particle layer on the wall. The conclusions and data obtained provide a theoretical foundation and empirical support for the design of innovative inlet chamber structures.

High-purity quartz is closely associated with strategic emerging industries, such as new-generation information technology, advanced materials, and new energy [...]

Chitosan-modified quartz sand accelerates the start-up of biofilter: insights into performance, microbial characteristics, and functional genes

Evidence of a glass-making workshop dating to the 11th century was unearthed in the Zemlyanoye Gorodishche district of Staraya Ladoga. The site yielded over 200 fragments of multicolored glass, along with chips from raw ingots, semi-finished products, technological waste, and sintered multicolored glass, distributed over an area of approximately 500 square metres within the central portion of the cultural layer. In addition, the remains of a production furnace, constructed from stones laid on a clay base, were uncovered. A piece of sintered white quartz sand, with its surface covered by a thin layer (up to 3 mm) of transparent glass, was found among the materials related to the workshop. The colored glass, sintered sand, and thin layer of transparent glass were analyzed using geochemical methods (pXRF, SEM-EDX, m-CT). The data obtained confirmed that both local and imported raw materials were used in the manufacture of glass products in the territory of Staraya Ladoga in the 11th century.

Coupled quartz crystal microbalance – Surface enhanced Raman scattering strategy for the design and testing of aptasensors for small analytes

Applying carbonated steel slag (CSS) as fine aggregates can not only effectively utilize the waste steel slag, but also has excellent CO2 capture potential. In this paper, the optimal conditions for pressurized carbonation of steel slag are obtained based on orthogonal experiments and the effects of CSS on the mechanical properties, thermal stability and microstructure of cement mortar at different substitution ratios are investigated through compressive, direct tensile, fracture toughness tests and multiscale microstructural characterization methods. The orthogonal experimental results indicate that the optimal condition for pressurized carbonation can be determined as 99.9% CO2 concentration, 0.5 MPa CO2 pressure and 18 h carbonation duration. Moreover, the addition of CSS can enhance the mechanical properties of cement mortar and promote hydration products, with the direct tensile modulus of CSS mortar being up to 28.91% higher than that of plain mortar. Overall, acceptable engineering properties can be obtained by replacing quartz sand with CSS in mortar, even under the highest replacement ratio of 100%.

The Upryamoye ore field is located in the Chukotka metallogenic belt in Northeast Russia. The orebodies are hosted within Late Jurassic–Early Cretaceous greenschist-facies metamorphosed rocks and structurally controlled by NW-trending fold-and-thrust dislocations. Based on geological exploration, petrographic, mineralogical, and geochronological studies, new data on the geological structure and composition of gold–quartz mineralization of the Upryamoye ore field are presented. Optical and scanning microscopy were used to study the lithological features of the host rocks and determine the ore textures and the morphology and internal structure of native gold, auriferous pyrite, and arsenopyrite. Qualitative and quantitative characterization of the ore minerals was carried out using SEM-EDS and EPMA. To determine the age of the gold mineralization, Re-Os dating of arsenopyrite and U-Th/He dating of pyrite were performed. The results show that the orebodies comprise carbonate–quartz and sulphide–carbonate–quartz saddle reef veins in both the fold hinge and limbs, as well as mineralized shatter zones and mylonite zones that trace thrust faults. The main ore minerals are arsenopyrite and pyrite, associated with minor amounts of galena, sphalerite, chalcopyrite, tetrahedrite, and bournonite. Native gold is distributed extremely unevenly, forming thin and finely dispersed inclusions in pyrite and arsenopyrite. U-Th/He isotopic analyses of auriferous pyrites suggest that gold mineralization in the Upryamoye ore field occurred at 123 ± 4 Ma. The data obtained by Re–Os dating of auriferous arsenopyrite are inconsistent with direct geological observations but indicate that Os in the arsenopyrite was derived from the crustal source. According to a number of characteristic features of mineralization, the Upryamoye ore field is attributed to a metamorphic genetic type of orogenic low-sulphide gold–quartz deposits. The ore-forming process was long and multi-stage, occurring during the final collisional phase and the beginning of the extensional phase of the Chukotka orogen.

To address the challenges of high impurity content and low whiteness in quartz sand, this study proposes a combined process of solid-state chlorination roasting followed by acid leaching. By using calcium chloride (CaCl2), a safe and low-cost solid chlorinating agent, mixed with quartz sand for chlorination rofasting, the process effectively removes key impurity elements such as aluminum (Al) and iron (Fe), thereby enhancing the whiteness of the quartz sand. The quartz sand used in the experiment had an aluminum content of 4519 ppm and an iron content of 496.3 ppm. Under optimized conditions—a mass ratio of quartz sand to CaCl2 of 1:0.1, a roasting time of 2 h, and a roasting temperature of 1100 °C—the contents of aluminum and iron impurities were reduced to 422.62 ppm and 124.43 ppm, respectively, although the calcium content increased significantly. Subsequent acid leaching further reduced the residual impurities and the introduced calcium elements. The results demonstrate that the combined process achieved removal rates of 91.1% for aluminum, 90.7% for iron, and 50.2% for calcium, while increasing the whiteness to 85.2 Wb. This approach exhibits significant advantages compared to standalone acid leaching or chlorination roasting. This approach exhibits significant advantages compared to standalone acid leaching or chlorination roasting, thus offering a viable technical route for the production of high-quality panel-grade quartz sand.